diff --git a/js/xpconnect/tests/unit/test_bug851895.js b/js/xpconnect/tests/unit/test_bug851895.js
new file mode 100644
index 000000000000..7cab5b12dcdb
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_bug851895.js
@@ -0,0 +1,11 @@
+const Cu = Components.utils;
+
+function run_test() {
+  // Make sure Components.utils gets its |this| fixed up.
+  var isXrayWrapper = Components.utils.isXrayWrapper;
+  do_check_true(!isXrayWrapper({}), "Didn't throw");
+
+  // Even for classes without |this| fixup, make sure that we don't crash.
+  var isSuccessCode = Components.isSuccessCode;
+  try { isSuccessCode(Components.results.NS_OK); } catch (e) {};
+}
diff --git a/js/xpconnect/tests/unit/xpcshell.ini b/js/xpconnect/tests/unit/xpcshell.ini
index a4b6c9da8d8f..4ede121a5b3e 100644
--- a/js/xpconnect/tests/unit/xpcshell.ini
+++ b/js/xpconnect/tests/unit/xpcshell.ini
@@ -18,6 +18,7 @@ tail =
 [test_bug813901.js]
 [test_bug845201.js]
 [test_bug849730.js]
+[test_bug851895.js]
 [test_bug_442086.js]
 [test_file.js]
 [test_blob.js]